Enhanced Production of Bacterial Cellulose from Miscanthus as Sustainable Feedstock through Statistical Optimization of Culture Conditions

Biorefineries are attracting attention as an alternative to the petroleum industry to reduce carbon emissions and achieve sustainable development. In particular, because forests play an important role in potentially reducing greenhouse gas emissions to net zero, alternatives to cellulose produced by plants are required. Bacterial cellulose (BC) can prevent deforestation and has a high potential for use as a biomaterial in various industries such as food, cosmetics, and pharmaceuticals. This study aimed to improve BC production from lignocellulose, a sustainable feedstock, and to optimize the culture conditions for Gluconacetobacter xylinus using Miscanthus hydrolysates as a medium. The productivity of BC was improved using statistical optimization of the major culture parameters which were as follows: temperature, 29 °C; initial pH, 5.1; and sodium alginate concentration, 0.09% (w/v). The predicted and actual values of BC production in the optimal conditions were 14.07 g/L and 14.88 g/L, respectively, confirming that our prediction model was statistically significant. Additionally, BC production using Miscanthus hydrolysates was 1.12-fold higher than in the control group (commercial glucose). Our result indicate that lignocellulose can be used in the BC production processes in the near future.

Evaluation of the Adsorption and Desorption Dynamics of Beet Juice Red Dye on Alginate Microbeads

The use of alginate microcapsules has often been mentioned as one of the ways to remove dyes from waste solvents, water and materials from the food industry. In addition, alginate can be used as a wall material for the microencapsulation of food dyes and their further application in the food industry. The aims of this study were to: (i) determine the effect of the alginate concentration (1, 2, 3 and 4%) on the ability of the adsorption and desorption of natural beetroot red dye and (ii) evaluate the kinetic parameters of the adsorption and desorption process, as well as the factors affecting and limiting those processes. According to the obtained results, the viscosity of alginate solutions increased with an increase in the alginate concentration. Based on k2 values (the pseudo-second order kinetic rate constant), when a more concentrated solution of alginate was used in the adsorption process, the beads adsorbed a smaller amount of dye. Furthermore, based on the values for n derived from the Korsmeyer–Peppas model, the dye release rates (k) were higher for beads made with lower alginate concentrations, and this release was governed by a pseudo-Fickian diffusion mechanism (n values ranged from 0.2709 to 0.3053).

The Layered Encapsulation of Vitamin B2 and β-Carotene in Multilayer Alginate/Chitosan Gel Microspheres: Improving the Bioaccessibility of Vitamin B2 and β-Carotene

This research underlines the potential of alginate multilayered gel microspheres for the layered encapsulation and the simultaneous delivery of vitamin B2 (VB) and β-carotene (BC). Chitosan was used to improve the stability and controlled release ability of alginate-based gel microspheres. It was shown that a clear multilayered structure possessed the characteristics of pH response, and excellent thermal stability. The sodium alginate concentration and the number of layers had notable effects on mechanical properties and particle size of gel microspheres. Fourier-transform infrared spectroscopy and X-ray diffraction analyses further proved that VB and BC were encapsulated within the gel microspheres. Compared with the three-layer VB-loaded gel microspheres, the total release of VB from the three-layer VB and BC-loaded gel decreased from 93.23 to 85.58%. The total release of BC from the three-layer VB and BC-loaded gel increased from 66.11 to 69.24% compared with three-layer BC-loaded gel. The simultaneous encapsulation of VB and BC in multilayered gel microspheres can markedly improve their bioaccessibility and bioavailability. These results showed the multilayer gel microspheres synthesized herein have potential for applications in the layered encapsulation and simultaneous delivery of various bioactive substances to the intestinal tract.

Characterization of the physical properties and sensory acceptability of Caulerpa racemosa grain beverage

Caulerpa racemosa grain was a healthy product and high nutrition. This study applied study was applied Caulerpa racemosa grain in the beverage with the addition of alginate powder. Thus, the present work was aimed to determine the properties of beverage C. racemosa grain formulated with the alginate concentration was varied (0; 0.025; 0.05; 0.075; 0.10 and 0.125 %). The testing of quality beverage C. racemosa viscosity was analyzed using viscometer methods. The colorimeter investigated the colour. The sensory acceptability hedonic and score method (colour, appearance, aroma, taste, texture, and overall acceptance) used a 5-point. Results showed that alginate used alginate 0.025%, the highest preference, aroma, and appearance scores. The addition of alginate increased alginate was increased the viscosity of beverage C. racemosa grain. The colour of C. racemosa grain progressively became light as the level of alginate grew. However, the increased alginate is not significant enough to change the redness and greenness value of C. racemosa grain beverage. The panelists have preferred to drink the selected Caulerpa grain beverage (concentration sodium alginate 0.025%), with slightly viscous.

The kinetics of Fe2+ heavy metal adsorption by microalgae Desmodesmus sp. beads

Industrial waste that contains high concentration of iron heavy metal (Fe2+) needs to be reduced into a safer limit for water ecosystem using an environmental-friendly, sustainable and low cost technology. This literature study was aimed to gather information on Fe2+ metal ion removal with biosorption method by mobilized beads-shaped Desmodesmus sp. green microalgae. Biosorbent beads are made of Desmodesmus sp. green microalgae powder binded with Na-alginate polymer. Desmodesmus sp. microalgae were cultivated in an Erlenmeyer flask with wastewater contains Fe2+ and Beijerinck growth media controlled in batch system. Analysis was conducted to study the influence of pH, size, beads, beads concentration, and Na-alginate concentration towards Fe2+ heavy metal removal efficiency on biosorption process. Research results revealed that Fe2+ heavy metal was effectively adsorbed by 1 mm beads up until 46% at maximum capacity on pH level of 6. These beads contain 8% gr/L of microalgae powder and 9% gr/L of Na-alginate. The involved function groups in Fe2+ sorption and the beads biosorbent morphology changes were analyzed by using FTIR and SEM. This biosorption research was following by analysis of Freundlich isotherm and reaction kinetics order two with linear approach. This was to shows the beads possess adsorption kinetics with optimum Fe2+ absorption capacity. Desmodesmus sp. beads are highly potential to be used as biosorbent since the heavy metal removal process was selectively conducted on wide pH level and temperature ranges, fast adsorption kinetics, and low operational cost. The smaller the beads size the wider the surface area, which leads to higher removal efficiency rate.

Antioxidant activity of Alginate Oligosaccharides (AOS) from Sargassum sp. for Improving the Cutaneous Wound Enclosure in Zebrafish (Danio rerio)

Sargassum sp. classified as brown seaweed which is known as an alginophyte (alginate producer). Alginate has undergone a depolymerization process called alginate oligosaccharides (AOS) and has been shown to have antioxidant activities to increase wound tissue recovery. This study aimed to determine the antioxidant activity of Alginate oligosaccharides (AOS) and their ability to improve the cutaneous wound enclosure in Zebrafish (Danio rerio). The IC50 value was used to calculate the ability of extract to inhibit free radicals using DPPH (516 nm). Zebrafish were immersed 12 hours before the injury and shortly after injury with a two factorial design, i.e., alginate concentration and immersion time. Zebrafish were immersed for 1 hour, 3 hours, and 5 hours with serial concentration of 200 ppm, 400 ppm, and 600 ppm, respectively. Morphological observations were carried out at the the first day, fourth day, tenth day, and twenty-first-day post wounding. The results of this study showed that alginate from Sargassum sp. has a yield of 40.5 ± 1.125% with a purity level of 89.95%. Based on antioxidant activity, alginate is categorized as moderate (178,377 ppm) and evidently has the ability to increase wound recovery compared to control. It has indicated by the formation of the wound enclosure.

Influence of Sodium Alginate Concentration on Microcapsules Properties Foreseeing the Protection and Controlled Release of Bioactive Substances

To understand the abilities of Ca-alginate microcapsules and their specific applications in different fields, it is necessary to determine the physicochemical and structural properties of those formulated microcapsules. In this work, we aimed to study the effect of alginate concentration in the improvement of the encapsulation efficiency (EE) and on the release of phenolic and flavonoid substances. The relationship between the structure of the encapsulated bioactive substance and Ca-alginate network and their effect on the EE and release kinetics have been investigated. The incorporation, structure, morphology, and phase properties of all elaborated materials were characterized by UV-spectroscopy, Fourier transform infrared (ATR-FTIR), scanning electron microscope (SEM), and X-ray diffraction (DRX). The results indicate that increasing the polymer concentration increases the EE and decreases the loading capacity (LC), whereas the effect of alginate polymer concentration on the release was not observed. The release study of bioactive substances showed that the release kinetics is relatively dependent on the structure and the physicochemical characteristics of the bioactive substance, which became clear when the encapsulated compounds were released from the core of calcium alginate microcapsules. Thus, it could be concluded that the pores size of the Ca-alginate network is smaller than the volume of the crocin molecule (2794.926 Å3) and higher than the volume of the gallic acid molecule (527.659 Å3). For the same microcapsules system, the release mechanism is affected by the structure and physicochemical properties of the encapsulated molecules.

Impact of Surface Topography, Chemistry and Properties on the Adhesion of Sodium Alginate Coatings Electrophoretically Deposited on Titanium Biomaterials

In this paper, we report on the electrophoretic deposition and characterisation of pure sodium alginate coatings on titanium biomaterials, the commercially pure titanium CP-Ti1 and Ti–13Nb–13Zr titanium alloy. Various solutions differing in the distilled water to ethanol volume ratio and sodium alginate concentration were used for coating deposition. Uniform, dense and continuous coatings with a thickness up to 1 µm were deposited. The effect of surface topography and morphology, wettability and surface free energy as well as surface chemistry on the coating adhesion to the titanium biomaterials were investigated. The coatings exhibited very good adhesion to the polished and then chemically treated alloy. The adhesion mechanisms were identified. The chemical bonding and interfacial adhesion mechanisms are plausible. The coatings exhibited low surface development, dependent on the applied substrate roughness. Sodium alginate coatings on both substrates showed moderate hydrophilicity and relatively high surface free energy, on average 30 pct higher in comparison with that of the substrate materials. The obtained results will be useful for the further development of composite sodium alginate coatings for enhancing the biological performance of titanium biomaterials.

Alginate/cartilage extracellular matrix-based injectable interpenetrating polymer network hydrogel for cartilage tissue engineering

In the present study, alginate/cartilage extracellular matrix (ECM)-based injectable hydrogel was developed incorporated with silk fibroin nanofibers (SFN) for cartilage tissue engineering. The in situ forming hydrogels were composed of different ionic crosslinked alginate concentrations with 1% w/v enzymatically crosslinked phenolized cartilage ECM, resulting in an interpenetrating polymer network (IPN). The response surface methodology (RSM) approach was applied to optimize IPN hydrogel's mechanical properties by varying alginate and SFN concentrations. The results demonstrated that upon increasing the alginate concentration, the compression modulus improved. The SFN concentration was optimized to reach a desired mechanical stiffness. Accordingly, the concentrations of alginate and SFN to have an optimum compression modulus in the hydrogel were found to be 1.685 and 1.724% w/v, respectively. The gelation time was found to be about 10 s for all the samples. Scanning electron microscope (SEM) images showed homogeneous dispersion of the SFN in the hydrogel, mimicking the natural cartilage environment. Furthermore, water uptake capacity, degradation rate, cell cytotoxicity, and glycosaminoglycan and collagen II secretions were determined for the optimum hydrogel to support its potential as an injectable scaffold for articular cartilage defects.

Kualitas Bulir Cairan Caulerpa racemosa yang Disalut dengan Na-Alginat dan Ca-Laktat

Caulerpa racemosa mengandung serat, vitamin, antioksidan, polisakarida sulfat, sulfat bebas, dan mineral sehingga dapat dimanfaatkan sebagai pangan fungsional. Namun, cairan C. racemosa mudah mengalami kemunduran mutu selama proses penyimpanan dan transportasi, sehingga perlu dipertahankan mutunya dalam bentuk bulir. Perlakuan yang diberikan dalam proses penyalutan adalah variasi konsentrasi Na-alginat 0,4%; 0,6% dan 0,8% dan variasi larutan Ca-laktat 0,4%; 0,6% dan 0,8% yang diulang sebanyak tiga kali. Tujuan penelitian ini untuk menentukan kombinasi konsentrasi Na-alginat dan Ca-laktat terbaik dalam mempertahankan mutu bulir cairan C. racemosa. Hasil penelitian menunjukkan bahwa cairan C. racemosa mengandung mineral, serat pangan, dan asam amino baik esensial maupun non esensial dengan kadar air cairan C. racemosa sebesar 97,77%±0,02% dan setelah ditambah air dengan rasio 1:4, kadar airnya menjadi 99,6%±0,61%. Perlakuan konsentrasi Ca-laktat berpengaruh terhadap kadar air dan kadar abu bulir yang dihasilkan, sementara kadar serat kasar bulir dipengaruhi oleh perbedaan konsentrasi Na-alginat. Nilai terbaik berdasarkan kadar serat ditemukan pada perlakuan kombinasi Na-alginat 0,6% dan Ca-laktat 0,8% sebesar 4,05% dengan kadar air 97,22% dan kadar abu 0,65%.ABSTRACTCaulerpa racemosa contains fiber, vitamins, antioxidants, sulfated polysaccharides, free sulfates, and minerals so that it can be used as functional food. However, C. racemosa liquid deteriorates easily during storage and transportation, therefore it is necessary to maintain the quality of C. racemosa liquid in encapsulated form as grain. The treatments given in encapsulation process were variation of Na-alginat concentration i.e. 0.4%; 0.6% and 0.8%, and variation of Ca-lactate solution i.e. 0.4%; 0.6% and 0.8% which were repeated three times. The aim of the study was to determine the best combination of Na-alginate and Ca-lactate concentrations in maintaining the quality of encapsulated C. racemosa liquid grain. The results showed that C. racemosa liquid contained minerals, dietary fiber and amino acids, both essential and non-essential, with moisture content of 97.77±0.02%. After added with water with a ratio of 1:4, the moisture content of C. racemosa liquid was 99.6%±0.61%. The treatment of Ca-lactate concentration affected the moisture content and ash content of the liquid grain, while the crude fiber content was affected by Na-alginate concentration. The best value based on fiber content was found in the combination treatment of 0.6% Na-alginate and 0.8% Ca-lactate (A6K8) at 4.05%, with moisture content of 97.22% and an ash content of 0.65%.